In response to RFA-DA-15-019 to develop and test the delivery of age-appropriate HIV-focused models within the seek, test, treat, and retain (STTR) framework, this application proposes to reach young substance-using, sexually at-risk, HIV nave, African American women aged 18 to 25 years old in North Carolina. High incidence of HIV and sexually transmitted infections (STIs) among these young women is driven by drug use, poor condom use, and structural factors such as stigma and lack of age-appropriate services for HIV/STI prevention and treatment. Most HIV/STI clinics are not equipped to provide substance abuse counseling or to effectively link young women to substance abuse treatment. Many of these young women continue to abuse substances, have recurring STIs, and remain at high risk for HIV due to a lack of protective skills and other comorbid and contextual conditions. We propose a mixed-methods approach to develop and test the efficacy and examine two delivery strategies of an age-appropriate, woman-focused HIV intervention initiated in HIV testing clinics that will provide risk reduction, empowerment skills, and linkage to substance abuse treatment. Consistent with NIDA's seek and test aspects of the STTR framework, we will seek young sexually active and drug-using African American women aged 18 to 25 in low-resource communities in three counties who have not tested recently or ever for HIV. To examine the efficacy of the interventions, we will collect measures on behavioral (i.e., drug and sexual risk, comorbidity, reproductive health, empowerment, treatment) and biological (i.e., HIV, STIs [gonorrhea, chlamydia], drug use, and pregnancy) outcomes. We will test the woman-focused intervention conducted in two formats, face- to-face and mHealth, within HIV clinics in three counties using a three-arm cluster-randomized design in which counties are randomized to (1) HIV counseling and testing (HCT) as the control, (2) the face-to-face format by HCT staff who will be trained to deliver the intervention (including activities to sensitize staff to age- an gender-related issues, stigma, and other structural barriers that reduce these young women's access to HIV/STI services and substance abuse treatment); and (3) the mHealth format that will be delivered on smartphones using an interactive app, an innovation that can be easily integrated into participants lives once they complete HIV testing. We plan to estimate the costs and examine structural outcomes regarding the acceptability and sustainability of the new face-to-face (in the clinic) and mHealth (on smartphones) interventions from both staff and participants. The overall impact of both of these formats, relative to HCT, will offer alternative gender-focused strategies as HIV prevention models in a new structure for young, substance-using African American women, and determine whether the new intervention is a more viable strategy for ensuring intervention sustainability and producing positive behavior and biological results.